Oil burning apparatus and method



Feb.r 2s, 1933. w, A RAY 1,899,396

on. ummm@ unmuus Aun lemon Filed oct. 24, 4195o A TTORNEYS.

Patented Feb. 28.1933

l UNITED;- sfm'ras'g PATENT fOFFlOE WILLIAM A. nAY, OF sAN FnANCIsCO, CALIFORNIA, AssIGNOn To RAY BURNER. con- FANY, OF sAN FRANCISCO, CALIFORNIA, A CORPORATION OF `nELAvrrAIaF.

OIJ BURNING APPARATUS AND METHOD Application tiled October 24, 1930. Serial No. 490,929.

This invention relates generallyv to apparatus and methods for the burning of oil fuel, such as are commonly utilized for kdomestic heating furnaces or for boiler installations.

In many oil burner installations it is necessary to operate the apparatus intermittently rather than continuously over long peri.

ods. For example when installed in domesing to-the nozzle. However after the apparatus has been at rest for several hours as during night time, all of the parts of the apparatus assume a relatively low temperature, depending` upon the temperature of the surrounding atmosphere, so thatfor a substantial interval following startingof the appa.

ratus from such a period of rest, the oil fed to the burnernozzle is relatively cold. Such a fluctuation in the temperature of the oil being fed to the burner nozzle is generally not adetrimental factor when the apparatus is being operated upon oil 'which is relatively light or which is-not highly viscous. However if it is attempted to operate such ap- I paratus on oil which is normally relatively viscous, commonly termed heavy fuel oil,

difficulty is encountered in maintaining a properly controlled oil feed. Thus if the apparatusv is started in operation when cold, the flow of highly viscous oil to the burner nozzle is reduced because of its resistance to flow. However after the apparatus has been in operation for a time and the parts adjacent the nozzle have become warm, the Oil being fed to the nozzle becomes heated in its flow, and thus the rate of feed tends to become greater. If'the apparatus is adjusted to .give a proper 1combustible mixture after lwhich preferably functions to supply oil at the parts have become warmed, the flow of oil to the nozzle when startingunder cold conditions may beinsuiicient to permit proper ignition. On the other hand if the apparatus is adjusted to secure proper ignition under cold conditions, then after the parts have become warmed the flow of oil increases to such an extent as to cause inefficient combus- It is an object of the present invention lto devise an oil burning apparatus and method which will make practical the use of relatively'heavy viscous fuel oil. The apparatus as described herein is relatively simple inconstruction and operation, and will operate satisfactorily over 'relatively long periods 5` Further objects and features of the invenwithout' requiring frequent servicing.

tion will appear from the following description in which the preferred embodiments of the invention have been set forth in detail in conjunction with the accompanying draw- A ing. It is to be understoodl that the appended claims are to be accorded a range of equivalents consistent with the state of the prior art. v y J Referring to the drawing:

Flgure 1 1s a side elevational view illustrating' diagrammatically apparatus incorporating the `present invention. v

Figs. 2, 3 and 4 are circuit diagrams for the electrical orifice heater.

The apparatus illustrated in the drawing consists genei ally -of an oil burner 10 of the oil atomizing type, an oil -supply means l1 a predetermined static pressure, and oil `flow control means 12. vAs representative of a suitable burner I have shown a nozzle -13 extended thru .the-wall 14 of a heating fur- .nace or boiler combustion chamber. When in operation a blast ofV air is delivered 4thru 10 nozzle 13 by a blower or fan, driven by suitable means such as an electric motor or steam turbine. (A rotating atomizing cup 16 is disposed `coaxiall within nozzle 13 and oil is su plied to this cup thru a suitable pipe 17.

en in operation oil delivered from'pi e 17 is thrown from the lip of cup 16 in t e form4 of a finely atomized spray which intery mingles withthe blast of air discharged thru nozzle 13, to form a combustible mixture.'- It is common practice with -such burners to form the nozzle, the blower, and the drivf ing motor or'turbine as a structural unit',

' and pipe 17 extends from this unit to a suitable tail piece or fitting.

As previously explained the oil supply means -11 is preferably adapted to deliver oil at an automatically controlled static fluid pressure, and therefore in the method of the present invention it is representative of a source of oil normally at a sustained static uid pressure. Structurally the specific `means illustrated consists of a .casing or 28, while the lower end is secured to the valve' member 26. p

Valve member 26 is normally biased towards closed osition, and in order toy permit adjustment o this blas, a plug 29is shown threaded into the casing closure 28. A screw 31 is threaded into plug 29, and the lower end of this screw is formed to engage the upr end of a compression spring 32. The ower end of spring 32 is seated upon the lower end of sylphon tube 27 so as to normally tend to urge this tube towards an extended osition. By loosening nut 33 screw 31 can e adjusted so as to vary the tension u n spring `32and thus vary the force with which. valve member 26. is urged 'toward closed position.

For continuously introducing oil into cas- -ing 21 about the exterior of sylphon tube 27,

during operation of the ap aratus, I have indicated schematically a sultable oil pum 36.' The outflow side of this pump is indicated as being connected with casing 21 by pipe 37, while the inflow side of the pump communicates with a suitable oil reservoir 38.

` Another suitable oil pump 39 has been indicated schematically, and this pump lhas its inflow side connected to an oil pipe line 41 .and its outflow side discharging into reser- 'voir 38. Pipe line 41 connectswi'th a suitable oil storage tank. Generally it is preferablethat pump 39 be of greater ca acitythan pump 36 and that both pumps ceeding the normal rate o are commonly riven by the same electric pable 'of noarmally motor or turbine which drives the blower o r fan of the burner 10. An overilow pipe 43 ajlso communicates with reservoir 38, and this pipe serves to return excess oil from the reservoir back to theoil storage tank. It is evident that in some installationsthe'reservoir 38, which can be termed an auxiliary reservoir, might be omitted. In this event only a single oil pump would deliver oil from the oil storage tank to the casing 21, while oil discharged thru port 23 would be returned to the oil storage tank.

Connection with the oil supply means 11 and the burner is established thru the pipe 44 which communicateswith the interior of casing 21. Another pipe 47 communicates thru. closure 28 with the interior of sylphon tube 27, for a purpose to be presently explained. It is evident that with oil pumps 36 and 39 operating at a continuous speed, oil will becontinuously-'pumped from the storage tank to the'reservoir 38, tind an excess of oil from this reservoir will be con tinually returned to the storage tank thru pipe- 43. Oil will also be continuously pumped fromi'reservoir 38 and delivered into casing 521, and since the amount of oil so delivered is in exceof the amount continuously removed thru pipe 44, fluid pressurewithin" casing 21, pressing upon the lower end of sylphon tube 27, tends to compress this tube and also spring 32, to lift valve member 26. `Thus in 'starting pumps 36 and 39 in operation, the' pressure within casing 2l -will build up to a certain predetermined value, after which valve member 26 will be automatically opened to permit bypassing a certain amount of oil back into reservoir 38. The result of such operation is that the fluid pressure within casing 21 and the Huid pressure of oil delivered thru pi 44 will be maintained above `a given hy rostatic pressure. 4This pressure can-of course be regulated by adjusting the position of screw 31.

The oil ilow control or compensating means 12 has been indicated as comprising a bod 51 made of suitable material having good eat conductivity, suchas metal. One

portion of the passageway ,52 in body 51is connected to fitting 18 by means of pipe 53, and another portion of this passageway is connected to oil pipe 44 as shown. An inner vannular portion 54Y is formed within bod 51,`

and this portion serves to provide a restrictedorifice 56 thru which oil owing thru body 51 must pass. One desirable form of orifice 56 1 s to taper portion 54, whereby the inner annulark orifice surface 57 is of restricted area. To provide suitable means for heating the inner surface 57 of the orifice I prefer to `employ an electrical heating element 58 which is normally disposed in. good heat transferring relationship with respect to the metal of body 51. This element 58 canV be provided with the usual electrical terminals 59 andv 61 for connecting the same to a suitable source of electrical current.

Suitable electrical connections for the heating element 58 are indicated in Fig. 2. In this instance the element is provided with two resistances 62 and 63, the resistance 62 of which is connected directly across the electrical current supply lines 64 and 66. In practice element- 58 is constructed so that it will utilize a relatively small amount of electrical energy, say inthe neighborhood of 40 watts, and in anA ordinary domestic furnace heating systems this element can be ,permanently connected -to the usual 110 .volt alternating current supply lines. If a greater amount of heat is required, both resistances 62 and 63 may be connected in shunt across the lines 64 and 66. h

.F ig. 3 indicates optional connections which can be made to effect a decrease inthe amount of heat supplied when` the apparatus is started in operation. In this case resistance 63 is connected .across line 64 and 66, while resistance 62 isconnected between line 64 and wire 67. Wire 67 and line 66 can be connected across the terminals of the electric motor 68, this motor being the one for driving the blower of the burner. Uponclosing of contacts represented by switch 69, motor 68 is started lin operation and resistance 62 is cut out. Connections of this kind can be employed where the boiler or furnace. room in 'which the burner is located is relatively warm when the apparatus is in operation.

The circuit arrangement shown in Fig. `4 serves to automatically increase the heat supplied to the orifice during operation of the burner,and can be utilized when the furnace or boiler room remains cold andf is not warmed to an appreciable degree during operation of the burner. In this case terminal l59 isconnected with line 66, and one of the terminals 61 is connected to line 64. The other terminal 61 together with terminal 59 is connected across the terminals of the motor 68. Upon closing switch 69,to start the apparatus is not in operation the inner sur faces of orifice 56 arealwaysv maintained at an`elevated temperature. Assuming now that the burner motor is started in operation and is accompanied by operation of the oil pumps 36 and 39, oil will be delivered from pump 36 into casing 21. Assuming that all of the parts of the apparatus are relatively cold, the oil willA be highly viscous, and in the absence of control or compensating means 12,

an insufficient amount of oil would be supplied to the burner to effect proper ignition. l However 1n my apparatus as the highly vlscous column of oil fiows thru orifice 56,-

-the outer periphery of this oil column is heated by the inner surfaces of this orifice 16. After the apparatus has been in operation for a considerable period and the parts have become heated to a substantial degree, the lbody of the oil delivered by pump 36 also becomes heated and thereafter the control or compensating means 12 has little if any effect upon operation of the apparatus. I

It will be noted' from the abogve that the' function and effect of control or compensating means 12, is to soaffect the flow charac-v teristics of highly viscous cold oil and to compensate for the tendency of the apparatus to deliver an insufficient amount of oil to the burner when started under cold conditions. In other Words with my apparatus adjustment can be made to secure a good combustible mixture under normal running conditions when the parts are heated, and when it is so adjusted a sufficient amount of highly viscous oil will be supplied 'to the burner when starting under cold conditions, to effect. proper ignition.

' It has been found that more effective control or compensation can be effected by the means 12 ifv the starting differential pressure between the inflow and outflow sides of the orifice'56 is maintained substantially constant. This result is made possiblev by the use of the pipe connection 47 which connects between the voutflow side of theorifice 56 and the interior of sylphon tube 27. Thus if the pressure in the outflow side of the orifice is relatively high, due to flow resistance thru the relatively small pipe 17, (a condition which is present when the apparatus is cold and the oil highly viscous), the static fiuid pressure transmitted-thru pipe 47 to the interior of `the sylphon'tube correspondingly increased with the result that the bias tending to close valve member 26 is in` creased. Thus a greater fluid? pressure is built up within casing or chamber 21 t0 ina crease the static fluid pressure upon the 1nflow side of the orifice. The converse ef-l fect takes place when the outflow pressure on the orifice decreases, 'as the partsiof the apparatus become heated sufficiently to heat the body of the oil. It is possible to operate the apparatus successfully without the pipe connection 47 between the outflow side of the orifice and the interior of sylphon tube= 27. However such a""connection has been lfound desirable, since itl makes possible betf ter control of the oil flow to`permit reliagble starting and continued operation `after starting with a good combustible mixture.

faces of the orifice in contact with the oil column flowing to the burner and maintaining the static fluid differential ressure between the inilow and outflow si es f theporiuce substantially constant In testimony whereoif, I have hereunto set l m hand.

y WILLIAM AQ RAY.

The heated orifice vwh-ich'I utilize with my apparatus is not to be confused Withauxiliary means for heating the body of oilosupplied to.

the burner. Such means require a relatively large amount of heat, and if electrical, require a relatively high electrical power con'- sumption. My heated orifice operates with sai d connection serving torestrict flow of oil to the burner, said orice having surfaces adapted to be heated to an elevatedtemperature, and means for heating the orifice.

2. In an oil burning apparatus, a burner` l adapted to burn oil supplied to the same, a source of oil normally at a substantially 'constant pressure having a pipe connection with the burner, and an orifice in said pipe connection serving'to restrict flow of oil to. the

burner, said orifice having surfaces adapted to be heated to an elevated temperature, and

means for supplying heat to the orifice.

3. In an oil burning apparatus, a bur'nerv i adapted to burn o il supplied to the same, a

source of oil normally at a substantially constant pressure having a pipev connection with the burner, and an .orifice in said pipe con,- nection serving'to restrict How of oil to the burner, and means for supplying heat to the v surfaces of said orifice.

4. A method of controlling flow of viscous oil from a source to an oil burnercomprising heating the outer surface of the oil column flowing to the burner from the source .while immediately restrictingthe filo/wing column at the point of heating of the outer surface of the flowing column. v

A method of controlling flow of viscous oil from a source to an oil burner comprising causing the oil from the source toflow thru a restricted orifice, andheatingfthe surfaces of the orice in contact willi the oilcolumn fiowing to the burner.

6. A method con olling flow of viscous oil from a source toan oil burner comprising causing the oil from the source to flow thru a restricted orifice supplying heat to the sur- 

